Numerous folding chairs are relatively popular, in part because they can be stored with considerably reduced space requirements when compared to non-folding chairs. Nevertheless, folding chairs still require relatively large space, since the dimension of the folding chair is generally reduced only along one space coordinate (e.g., reduced length). To further reduce the space requirement, collapsible chairs have been developed, in which further size reduction is achieved by folding the chair along at least two space coordinates (e.g., length and width). Various collapsing chairs are known in the art.
For example, Cook et al. describes in U.S. Pat. No. 5,921,621 a collapsible chair with a foldable backrest, in which the chair has four legs that support the corners of a flexible, square seat. The legs are movably attached to each other at about their respective midpoints, and the seat is collapsed in width and depth by turning the legs around the midpoint. While Cooks chair is relatively easy to unfold and collapse, Cook's chair provides relatively little stability and is prone to tipping over. Improved stability can be achieved by including slidable cross bars between the legs as described in U.S. Pat. No. 6,082,813 to Chen and U.S. Pat. No. 5,984,406 to Lee. Still further improved chairs with tensioned seats, solid armrests, and/or other advantages over previously known collapsible chairs are described by Zheng in U.S. Pat. Nos. 6,637,811, 6,607,240, and 6,302,479.
However, where the chair has an inverted calotte-shaped seat (a.k.a., moon chair or, Papason chair), collapsing of such a often chair becomes problematic. Therefore, most of such chairs are not collapsible at all, or can only be disassembled into the seat portion and one or more legs as, for example, described in U.S. Pat. No. 3,511,503 to Volpe or U.S. Pat. No. 3,964,790 to Bergeron. More recently, moon chairs have been commercially available (MAC Sports, Medium Moon Chair) in which the seat portion has a ring-shaped frame that is detachably coupled to a foldable leg portion, wherein both the ring-shaped frame and the leg portion are foldable when separated from each other. However, while such folding chairs generally provide a significant improvement in terms of reduced space requirement when not in use, several problems nevertheless remain. Most notably, the folding operation is often cumbersome as partial disassembly is required prior to folding the chair.
Therefore, while there are numerous moon chairs known in the art, all or almost all of them suffer from one or more disadvantages. Consequently, there is still a need to provide improved configurations and methods for collapsible moon chairs.